The objectives of this contract are to develop, maintain and distribute large quantities of extensively characterized cell cultures relevant to the conduct of research of aging. These include specially characterized diploid human fetal lung fibroblast lines (IMR-90, IMR-91, WI-38, TIG-1, and MRC-5); cultures from selected members of extensive pedigrees with familial Alzheimer's disease; normal human non-fetal fibroblast cultures derived from participants in the Baltimore Longitudinal Study over a span of ages from 17 to 96 years of age; cultures from individuals with segmental progeroid syndromes (Werner's, Hutchinson-Gilford, Cockayne, and Rothmund-Thomson); various nonhuman skin fibroblasts including nonhuman primates from 8 days to 27 years of age. Emphasis in recent years has been on development of fibroblast and endothelial cell cultures from the same donors, both human and nonhuman.